Drilling machine



May 11, 1965 A. G. WIGREN DRILLING MACHINE 3 Sheets-Sheet 1 Filed Feb. 5, 1962 INVENTOR. ALFRED 6. W/GREN ATTORNEYS BY g l y MUM/Z May 11, 1965 A. G. WIGREN DRILLING MACHINE 3 Sheets-Sheet 2 Filed Feb, 5, 1962 INVENTOR.

ALFRED a. W/GREN ATTORNEYS May 11, 1965 A. G. WIGREN DRILLING MACHINE 3 Sheets-Sheet 3 Filed Feb. 5, 1962 INVENTOR.

ALFRED 6. W/GREN QMQK ATTORNEYS *MWA, w

United States Patent C) 3,182,733 DRILLING MACHINE Alfred G. Wigren, 1425 Madison, El Cajon, Calif. Filed Feb. 5, 1962, Ser. No. 172,056 3 Claims. (Cl. 173-115) The present invention relates to a drilling machine of the type for drilling holes in the earth, and more particularly to drilling machines of the type in which the drill bit encounters relatively hard substances such as boulders and encounters cracks or crevices in boulers or other hard substances. The present application is a continuation-in-part of my copending application Serial No. 134,324, filed August 28, 1961, now abandoned.

. More particularly, the present invention relates to improvements in the standard type of drilling machines of the type having a mast which supports a vertical, trans latably movable jack hammer. Such jack hammer causes intermittent pounding on a shank which is fastened to the outer or upper end of the shank of a drill bit. This jack hammer is moved translatably, for example, downwardly as the drill bit is driven into the earth.

The drill bit, upon entering a crevice in a boulder, quite often becomes lodged. Further pounding on the drill rod or shaft will not release the bit, but, to the contrary causes further tightening of the bit in the crevice.

In practicing the present invention, the shank, which is attached to the upper end of the drill shaft, is provided with a downwardly facing shoulder, and, in accordance with the present invention, mechanism is provided on the jack hammer which, when the jack hammer is raised, is adapted to engage this downwardly facing shoulder for lifting the drill shaft and bit to thereby dislodge the bit from the crevice.

The lifting mechanism is in the form of a thrust hearing having an upwardly facing shoulder adapted to complement the downwardly facing shoulder on the drill shank. This mechanism is utilized for holding the drill shaft and consequently the drill bit at the desired height with respect to the boulder being drilled to thereby prevent the bit from traveling too far downwardly when the upper end of the striking bar is struck by the piston of the jack hammer.

If the drill bit is permitted to travel too far downwardly, when urged downwardly by the hammer, it is deflected, which causes either a lodging of the bit, or, if the bit engages a boulder at an angle, the course of the :hole being drilled is diverted from that desired.

Furthermore, the downwardly facing shoulder on the shank rests upon a resilient element and this element absorbs the shock which is imparted thereto by the piston of the jack hammer. This resilient element includes a thrust bearing which surrounds and lies below the shank. In the preferred embodiment, this resilient element is in the form of elastic rubber or synthetic rubber bumpers. This elastic tends to return the thrust bearing to its nonbiased posit-ion after completion of each of the hammer actions on the hammer shank, and when the thrust hearing is rendered effective, the impact of the piston of the hammer on the shank and consequently on the drill bit is lessened since part of the blow of the hammer is expended in compressing the rubber bumpers.

Other features and the advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings wherein a preferred embodiment of the invention is illustrated.

In the drawings:

FIG. 1 is a side view of the drilling machine, showing a fragment of the earth in cross-section and showing the drillbit striking a boulder at an angle;

FIG. 2 is a view of the drill bit and its relation toa "ice hidden boulder, but on a larger scale than is shown in FIG. 1;

FIG. 3 is the side view showing a fragment of the mast which supports the jack hammer, also showing the jack hammer attached to the mast, the lower part of the jack hammer being shown in section to show the reciprocating striking bar and the drill shank, and also showing the upper part of the drill bit;

FIG. 4 is a view looking in the direction of arrows 4-4 of FIG. 3;

FIG. 5 is a view looking in the direction of arrows 55 of FIG. 3;

FIG. 6 is a view looking in the direction of arrows 6-6 of FIG. 3;

FIG. 7 is a view looking in the direction of arrows 77 of FIG. 4; and

FIG. 8 is a view looking in the direction of arrows 8-8 of FIG. 4.

Referring more in detail to the drawings, the earth or ground is shown in FIGS. 1 and 2 at 20, the surface of the ground being indicated at 22. The drill machine is of the mobile type and is shown at 24, and the running gear includes the wheels 26. The drill machine 24, after being located, is suitably supported by a plurality of jacks, one of which is indicated at 28.

The drill machine includes a mast 30 which may be raised and lowered by a hydraulic jack 32. The mast supports a jack hammer 34 which may be raised and lowered through a chain 36. As an example, the mast is shown as extending vertically whereby the piston of the jack hammer 34 imparts vertical downward movement of the drill 38.

The jack hammer may be of any suitable type, and is herein illustrated as the Joy, Class TM-SOO, manufactured by the Joy Manufacturing Company of Pittsburgh, Pennsylvania, and shown in Operation and Maintenance Manual for the Joy, page 7, issued under Form No. CLT 192-9C-50504.

The jack hammer 34 includes a cylinder 40 in which the striking bar 42 reciprocates. The lower portion of the striking bar is shown in FIG. 3. The top of this striking bar is struck by a piston 43 of the pneumatic jack and is in threaded engagement with the upper part of the hammer shank 44 for driving the drill 38 downwardly. Such jack hammer per se does not form a part of the present invention, however, as will be explained hereinafter, difiiculties of proper operation are encountered which affect the operation of the striking bar, as for example when a boulder is encountered by the drill bit or when the drill bit becomes lodged in a crack or crevice of a boulder.

A thrust bearing supporting plate 48 is supported by a plurality of resilient and elastic elements which may be in the form of springs, but are herein shown as being formed of resilient rubber or synthetic rubber 50. Three sets of these elastic elements are provided, each including two rubber blocks. The plate 48 rests upon these blocks. The lower ends of these blocks are supported by washers 52 and these washers are supported by nuts 54 threaded onto bolts 56, 58 and 60 and held in place by lock nuts 62. The upper end of this bolt 56 is suitably secured to a bracket 64 on the cylinder 40, and bolts 58 and 60 are suitably secured to a bracket 66 carried by the mast. The bolt 56 is blocked in position by a nut 62 and the upper ends of bolts 58, 60 are locked in position by nuts 70. The plate 48 and elastic elements can be raised and lowered as a unit by screwing upwardly and downwarly, respectively, of the nuts 54 on the lower ends of the bolts 56, 58 and 60 whereby when in a desired adjusted low position, the thrust bearing is subjected to only a short vertical stroke by striking bar 42, i.e., the piston 43 is effective only during the bottom part of its stroke. The

resistance of the elastic elements is not changed by such shifting of the unit and consequently these elements are referred to as of the type which offer invariable resistance to impact.

As is more clearly shown in FIGS. 5, 6 and 7, the thrust plate 48 is formed of two sections 72 and 74. Each of these plates carries half of a thrust bearing 76, one of these halves being indicated at 78 and the other at 80. This thrust bearing is provided with a central hole 82 and a chamber is formed about the hole and is indicated at 84, one-half 86 being provided by the bearing section 78, and the other half 88 being formed by the section 80 of the thrust bearing. This chamber forms upwardly facing ring-shaped shoulder and will be hereinafter referred to at times as shoulder 34. The hole 82 is axially aligned with the axis of the cylindrically-shaped striking bar 42 and the cylindrically-shaped shank 44.

The shank 44, as is more clearly shown in FIG. 8, is provided with annular downwardly facing shoulder 96 which complements the shoulder 84 of the thrust bearing 76. Downward movement of the striking bar 42 imparts downward movement to the shank 44, which in turn imparts downward movement to the plate 48 through the thrust bearing 76. The shank 44 extends through the hole 82 of the thrust bearing 76 and the plate 48, and the lower end 92 thereof is internally threaded for receiving the upper end of the shank 94 of the drill 38. The lower end of the shank 94 carries the bit 96.

The thrust plate 48 is not used ordinarily, that is, the halves are open and therefore the shoulder 90 passes the plate freely. Obviously, as the striking bar 42 moves downwardly, it will impart downward movement to the bit 96. In operation, the entire jack is constantly lowered as the drill bit descends into the ground. The type of air hammer here employed is more or less standard and is provided with a mechanism (not shown) for causing rotation of the striking hammer and consequently causes rotation of the shank 44. Also, this type of jack hammer employs a hollow striking bar and a hollow shank 44; also, the drill bit shank 94 is hollow. In practicing the use of such type of air jack, air is forced downwardly through the striking bar 42, the shank 44 and the drill shaft 94 for blowing the dirt or dust away from the bit 96 during the drilling movement. It has been found in actual practice that when a boulder is encountered by the bit 96, the boulder will deflect the bit and the shank, thereby causing a devitation from the intended line of drilling. This is also true should be the drill bit encounter a crevice in rock formation in the earth. It has been found that by imparting relatively short strokes to the bit by limiting the extent of possible downward movement of the bit, a true course for the drilled hole can be maintained. In operation, as soon as it is discovered that the drill bit encounters a boulder or crevice, the bearing plate 48 is rendered effective.

As previously stated, in actual practice, the sections 72 and 74 are separated, normally. Quite often, when the drill bit strikes a crevice, it is lodged to such an extent that the shaft and drill bit cannot rotate although the hammer continues to function. In that event, the sections 72 and 74 are closed, as shown. Then the jack hammer is raised by the chain 36, causing the sections 72 and 74 to be raised through the rods 56, 58 and 60. Upward movement of the plate sections 72 and 74 causes the shaft 94 to be raised through engagement of the thrust bearing 76 with the shoulder 90 on shank 44. In this manner, the drill bit is dislodged.

After dislodging of the drill bit, the jack hammer is lowered at which time the position of the plate 48 and the thrust bearing 76, adjusted by nuts 54 in the lower ends of bolts 56, 58 and 60, is such, relative to the lowest extent of movement of piston 43, that the stroke of the striking bar 42 is foreshortened to foreshorten the extent of downward movement of the drill and this foreshortening is such that no binding takes place between the drill bit and the stone being drilled. The operator continues to lower the jack hammer as the cautious drilling proceeds. Of course, after the drill passes through the area where deflection tends to take place, the plate sections are swung outwardly so that the thrust bearing 76 is rendered ineffective.

While the function of the thrust bearing has been described with respect to the drill bit becoming lodged, it is to be understood that the operator will use the invention wherever needed. For example, when drilling in soft earth such as clay, a boulder may be encountered which could deflect the drill bit. The operator, upon becoming cognizant of striking the boulder, through the difference in sound created at the hammer, or otherwise, Will bring the thrust bearing into play and will retain the same effective until he is assured that deflection no longer will take place, at which time he will open the plate sections 72 and 74.

In any event, when the thrust bearing is rendered effective, the impact of the hammer on the shank and consequently on the drill bit is lessened since part of the blow of the hammer is expended in compressing the resilient bumpers 59. In this manner, the speed in the process of drilling is decreased or lessened to confine the drilling to the direction desired. Obviously, under this condition, that is while drilling through a boulder, the lowering of the jack hammer 34 is retarded commensurate with the speed of the drilling. The workman is skilled in determining the speed of lowering the jack hammer, principally by the sound created by the striking of the piston 43 upon the striking bar 42.

The ends 98 and 1430 of the sections 72 and 74, respectively, are held in position by clamp 102, one end of which clamp carries a pivot pin 104'which is rotatably mounted in the end 1% of the section 74. This clamp is C-shaped, including the legs 166 and 108 and the connecting yoke 110. The legs are attached to span the ends 98 and of the sections 72 and 74, and the yoke is provided with a screw 112 which when the tightened pulls the legs 98 and 100 into binding relationship. The bolt 56 extends through confronting half-circle notches 114 in the sections 72. and 74. The sections 72 and 74 are drilled as at 116 for receiving the bolts 58 and 60. The plate sections 72. and 74 are freely reciprocative with respect to the bolts 56, 58 and 60.

The ends 118 and 120 of the sections 72 and 74, respectively, are latched with one another through a bar 122. One end of this bar is pivotally mounted upon the bolt 58, and the other end is provided with a notch 124 for receiving the bolt 60. This bar is locked in position by nuts 126 on bolt 58 and by nuts 128 on bolt 66.

Also, it is apparent from the foregoing that by virtue of the present invention the depth of the strokes of the drill bit can be adjusted readily and shortened to such an extent that the drilling through a boulder or other hard substance can be elfected in the desired straight line, i.e., when the jack hammer is adjusted properly, the drill bit will not be deifected when striking, at an angle, a hard surface such as a boulder or upon entering an angling crevice in the earth.

While the form of embodiment herein shown and described constitutes a preferred form, it is to be understood that other forms may be adopted falling within the scope of the claims that follow.

I claim:

1. A drilling mechanism comprising, in combination:

(A) A hammer having (a) a vertically movable piston;

(B) a vertically movable drill bit;

(C) means connected with the drill bit and lying in the path of downward movement of the piston;

(D) and means for arresting downward movement of said first mentioned means and said bit, comprising: (b) a downwardly facing shoulder on said first mentioned means;

5 (c) an element having an upwardly facing shoulder confronting the first mentioned shoulder and engaged thereby; (d) and a support for said element, said support including:

( 1) elastic means, of the type offering invariable resistance to impact, for supporting the element having the upwardly facing shoulder; said elastic means and element being bodily movable as a unit, vertically relative to the hammer;

(2) and means for adjusting the height of said unit relative to the lower end of the piston of the hammer and for retaining said unit in adjustive position.

2. A drilling machine as defined in claim 1, characterized in that the shoulders are formed of hardened metal such as hardened steel.

3. A drilling machine as defined in claim 1, characterized in that said element comprises a (e) plurality of sections, each adapted to engage the first mentioned shoulder; and means pivotally carrying said sections about substantially vertical axes.

References Cited by the Examiner UNITED STATES PATENTS FOREIGN PATENTS 5/ 17 Great Britain.

BROUGHTON G. DURHAM, Primary Examiner. 20 CHARLES E. OCONNEL, Examiner. 

1. A DRILLING MECHANISM COMPRISING, IN COMBINATION: (A) A HAMMER HAVING (A) A VERTICALLY MOVABLE PISTON; (B) A VERTICAL MOVABLE DRILL BIT; (C) MEANS CONNECTED WITH THE DRILL BIT AND LYING IN THE PATH OF DOWNWARD MOVEMENT OF THE PISTON; (D) AND MEANS FOR ARRESTING DOWNWARD MOVEMENT OF SAID FIRST MENTIONED MEANS AND SAID BIT, COMPRISING: (B) A DOWNWARDLY FACING SHOULDER ON SAID FIRST MENTIONED MEANS; (C) AN ELEMENT HAVING AN UPWARDLY FACING SHOULDER CONFRONTING THE FIRST MENTIONED SHOULDER AND ENGAGED THEREBY; (D) AND A SUPPORT FOR SAID ELEMENT, SAID SUPPORT INCLUDING: (1) ELASTIC MEANS, OF THE TYPE OFFERING INVARIABLE RESISTANCE TO IMPACT, FOR SUPPORTING THE ELEMENT HAVING THE UPWARDLY FACING SHOULDER; SAID ELASTIC MEANS AND ELEMENT BEING BODILY MOVABLE AS A UNIT, VERTICALLY RELATIVE TO THE HAMMER; (2) AND MEANS FOR ADUSTING THE HEIGHT OF SAID UNIT RELATIVE TO THE LOWER END OF THE PISTON OF THE HAMMER AND FOR RETAINING SAID UNIT IN ADJUSTIVE POSITION. 